Most design documents describing a design submitted for fabrication involve either two dimensional drawings or three dimensional electronically generated and distributed solid models. The term ‘part design’ or ‘part’ may comprise objects for which specifications, such as engineering or manufacturing specifications, are necessary to properly manufacture the object. This may includes, but is not limited to machined, forged, or cast parts, commercial structures, bridges, highways, naval structures, articles of clothing, circuit boards, or any other manufactured item requiring manufacturing instructions to explain the fabrication process.
Both two-dimensional (“2D”) and three-dimensional (“3D”) design representations may contain information describing how certain features of design are to be fabricated, through the use of symbols that are universally understood to describe various specification types. Symbols may provide specification types such as weld types, diameter, flatness, cylindricity, circularity, straightness, surface finish, material, distance, and many other specifications used for a particular part and/or object. Sometimes, drawing notes must be written on a 2D drawing to add further critical information such as which manufacturing standards and regulations must be applied during the fabrication of a part. Currently, free-form information for a 3D solid model is saved in a different electronic file, thereby requiring a user accessing the 3D model design to access another file as well.
Business-to-business activity involving the communication of specifications for parts and/or objects may be very complex, with many opportunities for miscommunication of specifications associated with a given design. Some specifications necessary for proper manufacturing may be inadvertently left out of 2D drawings or 3D solid model files. In some cases, the engineer responsible for approving 2D drawings may approve a faulty design package because incorrect or missing specifications are overlooked.
Although the use of 3D solid models is increasing, many design packages sent to fabrication vendors for bid include only 2D drawings to represent the ‘official’ description of the design. Interpretation of a 2D representation of an inherently 3 dimensional object may be much more difficult than a representation that is itself 3D. Many times, the symbols and notes printed on a drawing are inadequate to completely communicate the intent of the designer. Misinterpretation usually leads to lengthy interaction with the designer or complete rework of an incorrectly fabricated part. This leads to tremendous waste in material, time, and money. In many cases, the current method of describing designs provides insufficient information to the fabrication vendor tasked with making the part.
Another problem associated with 2D drawings may be the drawing approval process. A person with approval authority, such as an engineer or designer, must carefully review each and every specification printed on a drawing. For very complex designs, there may be a large number of symbols, numbers, lines, and notes that must be checked against the design requirements. Inspection is typically a very tedious and time consuming process. A project that is behind schedule may force a quick review by the approving engineer, and errors may be overlooked. When an approval signature is given, it is applied to an entire drawing rather than to individual specifications, increasing the likelihood that faulty drawing packages will be forwarded for fabrication.
Three-dimensional solid models eliminate some of the interpretation issues associated with 2D drawings but the representation of individual specifications is still done using symbols. Furthermore, notes are usually applied to the part model as a whole and not to individual components within the model and then are typically not included in the electronic file containing the 3D graphical data. This means that the notes are even more detached from the visual information in 3D models than they are in 2D drawings.
The problem of approval signatures may be even more significant when dealing with electronic 3D solid models. Whereas a signature can be directly applied to a 2D paper drawing, such a capability may be more difficult for electronic models. When 3D models are used to convey ‘official’ designs, an approval signature is often applied to a control document that accompanies the electronic file containing the 3D solid model.
Other drawbacks may also exist.